Pressure Regulation

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

Pressure Regulator Valve

The pressure regulator valve regulates the pump output (line pressure) in response to a torque signal fluid pressure, which acts on the boost valve, the spring force, and the line pressure acting on the end of the valve. Line pressure is directed to the manual valve, to both accumulator valves, to the torque signal regulator valve, to the TCC regulated apply valve, to the temperature sensor in the Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.), and to the actuator feed limit valve. Also, line pressure feeds the converter feed fluid circuit through the pressure regulator valve.

Actuator Feed Limit (AFL) Valve

Line pressure is routed through the valve and into the actuator feed fluid circuit. The valve limits the actuator feed fluid pressure to a maximum pressure. Actuator feed fluid is routed to the pressure control solenoid and to each of the shift valves. The fluid also feeds the 1-2 signal and the 2-3 signal fluid circuits.

Pressure Control Solenoid (PCS) Valve

Controlled by the PCM, the PCS valve regulates the filtered actuator feed fluid pressure which acts on the end of the torque signal regulating valve.

Torque Signal Regulating Valve

IMPORTANT: Actuator feed fluid continues to feed the 2-3 signal fluid circuit through orifice #6. However, the exhaust port through the 2-3 shift solenoid valve is larger that orifice #6 in order to prevent a pressure increase in the 2-3 signal fluid circuit.

The torque signal regulating valve regulates the line pressure into the torque signal fluid circuit. Filtered actuator feed fluid pressure from the PCS controls this regulation. torque signal fluid pressure is routed to the accumulator valves and to the boost valve in order to control shift feel.